On the Absence of the Zeno Effect in Relativistic Quantum Field Theory

We study the time evolution of decaying particles in renormalizable models of Relativistic Quantum Field Theory. Significant differences between the latter and Non Relativistic Quantum Mechanics are found -in particular, the Zeno effect seems to be absent in such RQFT models. Conventional renormalization yields finite time behavior in some cases but fails to produce finite survival probabilities in others.